[PATCH kselftest-next 1/2] kselftests: memcg: update the oom group leaf events test

[PATCH kselftest-next 1/2] kselftests: memcg: update the oom group leaf events test

[Roman Gushchin]

Commit 9852ae3fe529 ("mm, memcg: consider subtrees in memory.events") made
memory.events recursive: all events are propagated upwards by the
tree. It was a change in semantics.

It broke the oom group leaf events test: it assumes that after
an OOM the oom_kill counter is zero on parent's level.

Let's adjust the test: it should have similar expectations
for the child and parent levels.

The test passes after this fix.

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
 tools/testing/selftests/cgroup/test_memcontrol.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index c19a97dd02d4..60bfe53c0289 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1002,7 +1002,8 @@ static int test_memcg_sock(const char *root)
 /*
  * This test disables swapping and tries to allocate anonymous memory
  * up to OOM with memory.group.oom set. Then it checks that all
- * processes in the leaf (but not the parent) were killed.
+ * processes in the leaf were killed. It also checks that oom_events
+ * were propagated to the parent level.
  */
 static int test_memcg_oom_group_leaf_events(const char *root)
 {
@@ -1045,7 +1046,7 @@ static int test_memcg_oom_group_leaf_events(const char *root)
 	if (cg_read_key_long(child, "memory.events", "oom_kill ") <= 0)
 		goto cleanup;
 
-	if (cg_read_key_long(parent, "memory.events", "oom_kill ") != 0)
+	if (cg_read_key_long(parent, "memory.events", "oom_kill ") <= 0)
 		goto cleanup;
 
 	ret = KSFT_PASS;
-- 
2.17.1

[PATCH kselftest-next 2/2] kselftests: memcg: speed up the memory.high test

[Roman Gushchin]

After commit 0e4b01df8659 ("mm, memcg: throttle allocators when
failing reclaim over memory.high") allocating memory over memory.high
became very time consuming. But it's exactly what the memory.high
test from cgroup kselftests is doing: it tries to allocate 100M with
30M memory.high value. It takes forever to complete.

In order to keep it passing (or failing) in a reasonable amount of
time let's try to allocate only a little over 30M: 31M to be precise.

With this change test_memcontrol finishes in a reasonable amount of
time:
  $ time ./test_memcontrol
  ok 1 test_memcg_subtree_control
  ok 2 test_memcg_current
  ok 3 test_memcg_min
  ok 4 test_memcg_low
  ok 5 test_memcg_high
  ok 6 test_memcg_max
  ok 7 test_memcg_oom_events
  ok 8 test_memcg_swap_max
  ok 9 test_memcg_sock
  ok 10 test_memcg_oom_group_leaf_events
  ok 11 test_memcg_oom_group_parent_events
  ok 12 test_memcg_oom_group_score_events

  real	0m2.273s
  user	0m0.064s
  sys	0m0.739s

Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
---
 tools/testing/selftests/cgroup/test_memcontrol.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index 60bfe53c0289..739fa90448f6 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -606,7 +606,7 @@ static int test_memcg_high(const char *root)
 	if (cg_write(memcg, "memory.high", "30M"))
 		goto cleanup;
 
-	if (cg_run(memcg, alloc_anon, (void *)MB(100)))
+	if (cg_run(memcg, alloc_anon, (void *)MB(31)))
 		goto cleanup;
 
 	if (!cg_run(memcg, alloc_pagecache_50M_check, NULL))
-- 
2.17.1

Re: [PATCH kselftest-next 1/2] kselftests: memcg: update the oom group leaf events test

[Chris Down]

Roman Gushchin writes:
>Commit 9852ae3fe529 ("mm, memcg: consider subtrees in memory.events") made
>memory.events recursive: all events are propagated upwards by the
>tree. It was a change in semantics.
>
>It broke the oom group leaf events test: it assumes that after
>an OOM the oom_kill counter is zero on parent's level.
>
>Let's adjust the test: it should have similar expectations
>for the child and parent levels.
>
>The test passes after this fix.

Thanks! Hopefully b59b1baa will also avoid this going unnoticed in future.

Reviewed-by: Chris Down <chris@chrisdown.name>

Re: [PATCH kselftest-next 2/2] kselftests: memcg: speed up the memory.high test

[Chris Down]

Roman Gushchin writes:
>After commit 0e4b01df8659 ("mm, memcg: throttle allocators when
>failing reclaim over memory.high") allocating memory over memory.high
>became very time consuming. But it's exactly what the memory.high
>test from cgroup kselftests is doing: it tries to allocate 100M with
>30M memory.high value. It takes forever to complete.
>
>In order to keep it passing (or failing) in a reasonable amount of
>time let's try to allocate only a little over 30M: 31M to be precise.
>
>With this change test_memcontrol finishes in a reasonable amount of
>time:
>  $ time ./test_memcontrol
>  ok 1 test_memcg_subtree_control
>  ok 2 test_memcg_current
>  ok 3 test_memcg_min
>  ok 4 test_memcg_low
>  ok 5 test_memcg_high
>  ok 6 test_memcg_max
>  ok 7 test_memcg_oom_events
>  ok 8 test_memcg_swap_max
>  ok 9 test_memcg_sock
>  ok 10 test_memcg_oom_group_leaf_events
>  ok 11 test_memcg_oom_group_parent_events
>  ok 12 test_memcg_oom_group_score_events
>
>  real	0m2.273s
>  user	0m0.064s
>  sys	0m0.739s
>
>Signed-off-by: Roman Gushchin <guro@fb.com>
>Cc: Chris Down <chris@chrisdown.name>
>Cc: Johannes Weiner <hannes@cmpxchg.org>

Thanks, this makes sense.

Reviewed-by: Chris Down <chris@chrisdown.name>